I think your kitchen is really looking pretty nice. I also think your sis might be on to something. When doing my kitchen, I was going to go for a taupe tile that really worked with the granite. (See srg215's backsplash--that's the one--I'm living vicariously through her). But then I thought about my desire to change colors in my space. I know I don't have the budget to re-do the backsplash when I tire of it. So I started thinking about white tiles. I was very determined not to get the white subway, and I found some pretty cool beveled Italian subways that had undertones of gray. I was ready to go for it. But that's when I found out I won the beveled arabesque tiles. I love that they jazz it up, but yet the color is white. In fact, I am currently (sorry guys) testing new paint samples. I've always wanted the gray color in the room to be a gray/lavender. I've got samples in the car right now. My point is, that with neutral bones, you really can do anything with the room. And neutral bones do not make the room boring or bland. So, I've posted a link to the photos of my kitchen and "not so boring white backsplash" in case you haven't been bored to death by them already. I'd post them directly here, but I can't torture the GW friends anymore! Look at the details, notice that except for the granite, eveything can be changed to a new color scheme. And this granite goes with any color--lime green, orange, blue, brown, black, gray, white, and on an on. Here is a link that might be useful: The pro photos

By all means, no splash on the window wall! The functional purpose of the backsplash is to protect the wall against grease and other food splatters coming from the range/cooktop or water from the sink. Even so, there are those (like me) who've had backsplashless kitchens for years and the walls get along just fine. Especially if you're not using those counters on your window wall for cooking or cleaning tasks involving water, I'm thinking your drywall will be ok there without a backsplash. In addition, your backsplash will end in a logical place, the overall design will be neat and simple and you will save you money! Now, if only I could be so objective about solving my own backsplash problem in a galley kitchen with a bay window wall at one end. :)

Mexican white 'field tile" and accent tiles from http://www.finecraftsimports.com/ fine Crafts and Imports out of Camarillo, CA. GREAT company to work with BTW! We got the mural here https://mexican-tile.net/Kitchen-Tile-Mural-Mexican-Kitchen--P2317632.aspx , also a good company; albeit a bit slow, but the mural comes from Mexico. BTW, Suggest you have a pro install the mural, because if you break one of the mural tiles you are SOL........

Are you determined to paint your cabinets? As Sina says, it's expensive and if you updated your appliances and range hood, added a backsplash, new hardware, undercabinet lighting, and just declutter the cabinet tops and counter, you'd have a new kitchen! Your cabinets harmonize very well with your floor, which is your fourth wall. Your wall paint doesn't quite blend well with the current cabinets or the floor--you need something warmer to tie into the floor in any case. Here's a galley kitchen with birch cabinets in case you decide to spend your budget on updated appliances. Open shelving isn't for everyone, but in galley kitchens they can be very practical--no dueling cabinet doors but only if you have nice dishes, glassware to display and are very organized about them. Below are some other birch cabinet kitchens just for wall color and backsplash. (Plain subway in a warm color that goes with the floor and countertops are a good way to go. Tile has to work with countertop, cabinets, floor--all three or you'll get a mish mash. Take a really close look at your second photo--the closeup of the cabinet, countertop, floor. They all harmonize. Your countertop is very speckled black, so the backsplash should be simple--not too much contrast or pattern. Also add undercabinet lighting.) Here's a palette that could work with stainless hardware. Something you could do now is change out the dated hardware, which should match your appliances--nickel if you go stainless; black if you keep your black appliances. Think about a counter-depth fridge, which works better in a galley kitchen than a deeper on. In the meantime, totally declutte your coutertops and remove all those objects on top of the cabinets to let the soaring ceiling star on its own. Cost? Zero.